People who have been watching the extreme weather in the Northern hemisphere might be wondering about the cause and if it might repeat itself. Drought in California, ice in Texas and floods in the UK, all at the same time and all record setting extremes . The cause is the loss of sea ice in the Arctic which is having an affect on the jet stream. A shortened explanation is here http://www.climateoutcome.kiwi.nz/ice-melt.html For a much more detailed explanation watch Jennifer Francis give her presentation. We are down to around four million square kilometres of ice compared with the original eleven million but if we get down to two million we will be in real trouble.